1. Field of the Invention
The present invention relates to toys, particularly to toy vehicles which move along tracks.
2. Description of the Related Art
Toy vehicles which move along tracks have long been popular among children and adults who are young at heart. One type of such toy applies the motive force to the vehicle via electrical current supplied through the track to the vehicle. Common electric toy trains and electric car racing sets work in such a manner.
A second type of such toy applies the motive force to the vehicle via gravity. The toy vehicle is released from a high portion of track and rolls along the track until the potential energy in the vehicle is dissipated by friction between the wheels of the vehicle and the track.
A third type of such toy provides motive force to the vehicle through a single rotating drum or a pair of rotating drums located in at least one position along the track.
One problem associated with all of the types of toy vehicles and tracks is that the wheels and axles will tend to attract foreign matter such as dust and grease. This will tend to hinder the rotation of the wheels, thus decreasing the speed at which the vehicles can travel along the track. Another problem is that the wheels are small and protrude from the vehicle, making them potentially harmful to very small children who may inadvertently separate the wheel from the vehicle and swallow the wheel.